Field of the Invention
The present invention relates to a printing apparatus capable of conveying sheets to a sheet processing apparatus, a method of controlling the same, and a storage medium.
Description of the Related Art
Conventionally, there has been known a sheet processing apparatus that performs saddle stitching in which after stapling the center of a plurality of sheets, the stapled sheets is folded into two to thereby output the sheets in a booklet form (see Japanese Patent Laid-Open Publication No. 2010-168134). In the sheet processing apparatus, as shown in FIG. 23, sheets conveyed from an image forming apparatus are discharged onto one of stacking trays 101 and 102 and a saddle-stitched product tray 103 according to the type of a finishing process set by a user. For example, when no finishing process is to be performed, the sheets are discharged onto the stacking tray 101. When normal stapling is to be performed, the sheets are discharged onto the stacking tray 102, whereas when saddle stitching is to be performed, the sheets are discharged onto the saddle-stitched product tray 103.
Further, there has also been proposed a sheet processing apparatus constructed as shown in FIG. 23 such that a conveying path for performing stapling and a conveying path for performing saddle stitching are made at least partially common, thereby achieving downsizing of the apparatus. For example, this apparatus employs a method in which when performing the saddle stitching, a sheet introduced into the conveying path, denoted by reference numeral 104, for performing stapling is switched back by reverse rotation of a conveying roller pair 106, and is guided into the conveying path, denoted by reference numeral 105, for performing saddle stitching.
By the way, due to the mechanical limitation of the sheet processing apparatus, there is a limit to the number of sheets on which the apparatus can perform saddle stitching. Conventionally, in view of a case of input of image data for sheets in excess of the number that can be saddle-stitched, there has also been proposed an image processing apparatus configured to automatically change a discharge destination of sheets from the sheet processing apparatus, to thereby prevent the sheets from being conveyed to a saddle stitching section (see Japanese Patent Laid-Open Publication No. 2002-331730).
However, in the sheet processing apparatus constructed as shown in FIG. 23, when image data for sheets in excess of the number that can be saddle-stitched is input, if the discharge destination is automatically changed from the saddle-stitched product tray to the stacking tray, it is impossible to obtain a product intended by the user.
Further, when post processing offline is performed after completing only discharge of the sheets of a product onto the stacking tray even though the product is not as intended by the user, if the sheets printed with an image layout intended for discharge onto the saddle-stitched product tray are discharged onto the stacking tray, the user is required to manually change the order of the sheets of the product. The manual operation is very troublesome for the user.